Plunger-elevator.



PATENTED DEC. 3, 1907.

cr. w. BROWN. PLUNGER ELEVATOR.

APPLICATION FILED FEB. 6. 1904.

Witnesses;

run: mmms PETERS co., mun/10mm;:1v c.

JOHN WALTER BROWN, OF LONDON, ENGLAND.

PLUNGER-ELEVATOR.

Specification of Letters Patent.

Patented Dec. 3, 1907.

Application filed February 6.1904:- Serial No. 192,430-

To all whom it may concern:

Be it known that I, J OHN VVALTER BROWN, a subject of the King of Great Britain and Ireland, residing at 57 Gracechurch street, in I the city of London, England, civil engineer, have invented new and useful Improvements in Plunger-Elevators, of which the following is a specification.

In working lifts or elevators, it 'is common to employ hydraulic motors or electric motors. The former possess great advantages in respect to safety, ease of control and low cost of maintenance, while the latter are re markable for their economy in the cost of working.

The object of my invention is to combine the advantages of both systems.

The accompanying drawing illustrates the application of my improved system of working to lifts of the ram-supported type.

The cage A is supported by a ram B working in a cylinder C, the latter being connected to a displacement cylinder 0, the ram D of which serves to raise the cage. \Vhile raising the cage A the ram D is assisted by pressure water which arrives from pumps E by way of the lifting cylinder 6, and forces water from the displacement cylinder 6 into the ram cylinder C, an electric motor J being applied to augment the pressure of the water in the displacement cylinder 6. In order to permit the cage to descend, the pressure water is released from the lifting cylinder 6, by means of a controlling valve G, flows by way of a pipe q into the pumps E, returns by way of the pipe g to the controlling valve G, whence it passes to the-lowering cylinders e e by way of the pipe 9. The pressure water on its entry into the cylinders e e raises the rams e 6 together with the ram D and per- Inits the discharge of the water from the lift cylinder O to lower the cage.

The cage, ram and half the load may be counterbalanced by means of weights applied to the displacement ram D; or a portion of the weight of these parts may be independently counterbalanced.

Between the controlling valve G and the pum s E a by-pass valve M is provided, whic may be combined with the controlling valve G, or may be connected to the hand rope a or other apparatus for working the controlling valve. In the construction illustrated the valves G and M are actuated by levers a a respectively connected to each valve and operated by the hand rope a.

To make up for water lost by leakage past the glands or otherwise, the suction-pipe 9* of the pumps E is connected with a tank K and furnished with a non-return valve 1).

The action of the apparatus is as follows The motor and pumps being started, the bypass valve M having been previously opened, the cage A with its load is raised by putting the pipe 9 of the lifting cylinder 0 in communication with the delivery pipe g of the pumps E, and the lowering cylinders e c in communication with the suction pipe g of the pumps, through the controlling valve G, the by-pass M being simultaneously closed. For lowering the cage and load, the communications are of a reverse character; the lowering cylinders being connected to the delivery and the lifting cylinder to the suction of the pumps.

What I claim as my invention and desire to secure by Letters Patent, is

In a direct acting lift-system, the combination, with a cage, ram and cylinder, and a balance weight for the cage, ram and approximately half the load, of a closed hydraulic circuit, a displacement cylinder and plunger, lowering cylinders and plungers, a pump for augmenting the pressure according to the duty required, an electrical motor for actuating the same, a main valve, a by-pass for short circuiting the pump, a valve therefor, and a lift-rope for said valves, said main valve being constructed and arranged to direct the discharge from the pump either to the displacement plunger or to the lowering cylinders, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN WALTER BROWN. 

